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MG MGB Technical - Sagging suspension

Hi all, finally after much help from yourselves my MGB Roadster is MOT'd and on the road, however ive noticed on flat ground the car leans to the left(viewed from the front)she actually sits about an inch lower on the one side. It had new rear leaf springs about 18 months ago and the armstrong front units are leak free and have new oil in them. Is it possible for the front coil spring on that side to have weakened as it looks ok with no fractures??
S Taylor

If you have replaced rear springs then leaning is the norm. Quality is very variable to say the least. A sag on the drivers side is the way B's usually go any way. The tank is off-set that way and most of the time they have only the driver. Swap the rear springs over and see what happens. When you take them off lay them down (Eyes down) and compare them, I doubt they will match. Coil springs are more reliable, in as much as they tend to sag at the same rate!!!! The dampers have no effect on ride height.
Allan Reeling

But Allan...LHD MGBs also have the "batchelor's droop"...so I doubt if the tank location has much to do with it. Cheers.
Rick Ingram

Cheers for the info, the o/s/f is what concerns me more as like i said its a good inch lower, where as the rear on the same side seems much the same as the opposite side. I totally agree about leaf spring quality and B's mainly have the driver in them but i would of thought for the o/s/f to be low the o/s/r should be the side with the good leaf spring thus pushing the front down??
S Taylor

ST, you didn't actually say that it was the front only that was low, as 90% of uneven stance is generated from the leaf springs. BUT the last set of coils I fitted to my roadster just carried on "relaxing" and had to be replaced 3 times before I found a pair remained "up".
Rick, glad to hear the dreaded droop afflicts you yanks!! The tank position does have an effect though, but not as much as a driver. When it becomes really pronounced I swap them over.
Allan Reeling

A problem at one corner could affect the diagonally opposite corner, i.e. you could have a high left rear rather than a low right front.

I spent sometime on the same problem with someone else recently, and it turned out his was due to some problem with the right front chassis rail, which he has had to live with. Try supporting both rear corners e.g. under the chassis rails or spring front hangers at the same height then measuring the fronts, then support both front chassis rails at the same height and measure the rears. Measure from the bottom of the trim strip to the centre of the hubs, and to the floor, and from the chassis rails to the floor, to try and work out where the differences lie.

I've had no problem with differences in replacement rear spring balance, but I have with replacement coil springs. One pair I bought were different free heights sitting on the counter. I politely asked if I could have two the same, which he got for me, saying "It won't make any difference" and he was right i.e. they were still slightly different on-car. They also had a higher free height than the book value, were ridiculous when first fitted, settled a bit on a trip over the many road humps we have round Solihull, and settled to a more acceptable (but still high) level over the next few thousand miles. Even though the usual complaint is rears being way too high from over hardening or over arching (possibly to do with compensating for heavier occupants these days) the three sets I've had for various reasons were actually too low with the roadster fully laden, and I've had to cut and shut the rear shackles to extend them by an inch or so to stop reduce bottoming and grounding - and that's with the Navigator and I just within the *original* weight allowance for occupants at an average of 150lb each.
PaulH Solihull

Thanks for the info, weather permitting (its pretty cold and wet here) im going to try swopping the rear spring left to right and see if that helps otherwise i'll source some new front springs in the new year, the car handles fine just looks odd so im in no great hurry...there loads more important jobs on the old girl like getting the boot lid to sit better.
S Taylor

when you work out "getting the boot sit better" let me know how it's done!
MGmike
M McAndrew

My boot lid sits high on the rear so much so i can push my fingers under it into the boot, as you can imagine i get a bit of water in the boot so continually need to mop it up. A friend of mine briefly looked at it who whos a panel beater and he thinks its down to poor alignment of the stainless boot rack thats fitted (not by me)causing the boot lid to distort...im going to take it off so i'll let you know how things go.
S Taylor

Try jacking it up front then back, but centrally, ie rear under the diff and front under crossmember. See if you can locate the list to the F or R suspension.
Art Pearse

Re boot lid, mine wasn't so high it leaked but the front left-hand corner was definitely too higher than the right and the surround at that point. I put a couple of washers between the hinge and the underside of the surround which spaced it downwards nicely. Depending on how much you have to space it you may need longer bolts.
PaulH Solihull

Paul you said that you cut and lengthened the rear shackles to help prevent bottoming out. Can you give me a little more information on how you did this as I have a similar problem on my TF.

thanks

Andy
Andy Preston

Hi Andy, have a look at http://www.mgb-stuff.org.uk/ridetext.htm#extend
PaulH Solihull

Paul many thanks for your advice and wonderful website which is very useful.

Many thanks

Andy
Andy Preston

My pleasure, Andy.
PaulH Solihull

This thread was discussed between 13/12/2012 and 20/12/2012

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